Collapsible structure



FIG. 1 is a perspective view of a first embodiment;

FIG. 2 is a right side elevation view, the left side elevation view being identical;

FIG. 3 is a front elevation view, the rear elevation view being identical;

FIG. 4 is a top plan view;

FIG. 5 is a bottom plan view;

FIG. 6 is a perspective view of a second embodiment;

FIG. 7 is a right side elevation view, the left side elevation view being identical;

FIG. 8 is a front elevation view, the rear elevation view being identical;

FIG. 9 is a top plan view; and,

FIG. 10 is a bottom plan view.

The very small break lines illustrated on the top, bottom, and side outside edges of the collapsible structure represent stitching. 

The ornamental design for a collapsible structure, as shown and described. 